Over 50% of adults older than 65 years report problems sleeping and the prevalence of persistent insomnia is estimated to be over 30% in this population, and steadily increases with age. Behavioral treatments for chronic insomnia have demonstrated consistent improvements in self-reported sleep, but outcome assessment, including polysomnography, behavioral factors such as health functioning and biologic factors impacted by sleep have not been comprehensively examined, especially in older adults. In particular, one promising area of research is the impact of interventions on energy balance. The hormones ghrelin and leptin are thought to convey information about energy balance to the brain, and dysregulation of these hormones lead to increases in appetite and lipid accumulation. Epidemiologic studies have found that poor sleep is associated with elevated ghrelin and decreased leptin, corroborated by experimental sleep restriction studies as well. Elevated ghrelin and decreased leptin levels also correlate with increased sympathetic activity; which is seen in insomnia patients. Taken together, these findings indicate that older insomnia patients may have altered energy balance. Yet few studies have measured objective sleep assessment following insomnia interventions and no study has reported its effects on energy balance. The proposed project is an ancillary study to a newly funded NIA randomized, controlled trial comparing the effects of cognitive-behavioral therapy (CBT), Tai Chi Chih (TCC), and hygiene/education control (EC) on sleep outcomes in older insomnia patients. This K23 project is an opportunity for the PI (a health-clinical psychologist) to utilize expertise in sleep and psychophysiology assessment and previous clinical training while developing expertise in behavioral insomnia treatment research and biological effects of treatment. The unique aims of this K23 project are to: 1) evaluate the effects of CBT vs. TCC vs. EC on ghrelin and leptin levels at baseline, mid- treatment, post-treatment and 3- and 12-month follow-ups; 2) determine the effects of CBT vs. TCC vs. EC on nocturnal autonomic function (power spectral analysis of heart rate variability) during sleep assessments at the UCLA GCRC at baseline and post-treatment; 3) examine whether energy balance and autonomic function are related to improvements in objective and subjective measures of sleep over the course of the treatment trial. [unreadable] [unreadable] [unreadable]